Freezing and thawing bag, mold, apparatus and method

ABSTRACT

A mold is disclosed for forming a freezable and thawable bag of uniform thickness, especially useful for cryopreservation of thermolabile substances. The mold features one or more recessed planar surfaces, including radiused peripheral walls about the recesses, a planar top surface, and means for conforming a blank sheet to the mold. Two mold halves combine to form a completed bag. The mold halves may be complimentary.

FIELD OF THE INVENTION

The following invention relates to an apparatus for forming flexiblebags, a method for forming the flexible bag and the bag itself. Morespecifically, the following invention relates to bags to containthermolabile and/or cellular biological substances and formed such thatthey can withstand stresses at extremely cold, cryogenic temperatures,reduce heat invasion from a higher ambient temperature into a pluralityof such bags placed together, reduce storage space required for aplurality of such bags, and provide a thin and substantially constantcross-section for the bag so that the rate of heat transfer into and outof the bag is substantially homogenous throughout the contents of thebag thereby providing an improved means of protecting the viability ofliving cells during freezing and thawing.

BACKGROUND OF THE INVENTION

Preservation of blood, cellular biological substances, tissue and otherthermolabile products frequently involves product maintenance atextremely cold temperatures. Cellular biological substances are thefundamental, structural and functional unit of living organisms.Thermolabile substances are those substances which are easily altered ordecomposed by heat. One economical mode for containment involves the useof encapsulating plastic since plastic is relatively inexpensive andlends itself to mass production techniques. However, many plasticssuffer from brittleness at extremely low cryogenic temperatures andseams are sometimes susceptible to fracture.

In addition, bags that are formed either by folding over a planarmaterial and seaming along peripheries or layering two planar materialsand seaming along the peripheries have a generally ovoid shape whenfilled with a liquid. This is because the cross-sectional area adjacenteither the fold or the seam has an area of decreasing cross-sectionalwidth as it tapers from the center. While for many applications, thistype of narrowing is unobjectionable, for certain biological fluids suchas white stem cells, a bag having non-uniform thickness along itscross-section may impair the integrity of the biological product,particularly during temperature changes. One reason for quality lossduring a change in temperature may involve the differential thermalgradient within the thermolabile or cellular substance caused byvariations in thickness induced by the geometric shape of the bagitself. Stated alternatively, the center portion of the bag is thickerthan the edges.

A corollary to the above-enunciated problem entails the fact that theprior art bags, with their thicker center portions, also provides anon-planar surface on opposing sides of the bag. This results in a "highspot" which also makes uniform temperature alteration of the contentsdifficult especially when heat exchange is attempted by contact with asubstantially planar surface that provides the heat gradient. Becausethe bag has a high area, uniform contact along the entire cross-sectionof the surface will have been precluded.

FIG. 8 reflects prior art bag structure and highlights the inherentproblems associated therewith. The radio frequency seam S is thinnerthan the non-seamed plastic forming the bag and has its weakest point Wat an edge of the seal closest to the interior I. When the product Pbegins to freeze, the product freezes first at the thinnest part of thebag, i.e. at edge E. Freezing proceeds inwardly, from the outside in,until an unfrozen core C exists. As the core C freezes, it expands andgenerates forces F which collimate and focus on the edge E because ofthe geometrical configuration of the bag. The force F frequently causesbag rupture at the weakest point W because the wedging force appearingat edge E tries to separate the seam with a turning moment M. Recall thebag material tends to become brittle at low temperatures, exacerbatingthis problem.

FIG. 13 reveals a further site of prior art bag weakness. When an accessport tube T is to be fitted to the bag, two horseshoe-shaped RF horns Hclose on the plastic membrane around the tube T and then the membrane atthe seal area S. This causes another weakened area W where bag failurescommonly occur.

SUMMARY OF THE INVENTION

The instant invention addresses all of the difficulties notedhereinabove. One manifestation of the problems solved includes theformation of peripheral seams circumscribing the bag which areappreciably stronger than prior art seam structures. Preferably, the bagis formed from two symmetrical sections, each vacuum formed to provide amajor wall flanked by a radiused end wall section and circumscribed by aperipheral flange. It is contemplated in one form of the invention thattwo half portions defining a plane of symmetry are thus formed andadhered together so that the peripheral flanges are in mating registryand sealed such as by means of adhesive, ultrasonic, R.F. welding orother means. The increased surface area of the peripheral seam flangecoupled with the radiused end wall interposed between the seam flangeand the major wall of the bag dissipate forces which in prior art bagscould have lent themselves to rupture at the seam area.

By vacuum forming the two halves, the contour of the side wall can becarefully controlled to make them substantially planar. Thus, when thetwo halves are united, a container having substantially uniformcross-section substantially along the entire extent will have beenprovided. This geometry encourages uniform thawing, freezing andimperviousness to the stresses that attend the seams and the radiusedend wall at cryogenic temperatures. This geometry also provides spaceefficient storage and reduced heat invasion from a warmer ambient mediumwhen the plurality of bags are placed with their planar surfaces incontact with each other.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the present invention to provide auseful and novel bag for containing thermolabile or live cell products,a method for making same and an apparatus associated with the formationof the bag.

A further object of the present invention is to provide a device ascharacterized above in which the seams associated therewith have greaterstrength to improve the integrity of the bag.

A further object of the present invention is to provide a device ascharacterized above in which the major surfaces of the bag are closelyspaced, parallel and substantially planar thereby increasing thelikelihood that heat transfer along those planar surfaces will moreuniformly alter the temperature profile of the contents within the bag.

A further object of the present invention is to provide a device ascharacterized above which lends itself to mass production techniques, isextremely safe to use and is durable in construction.

A further object of the present invention is to provide a device ascharacterized above which is substantially rectangular so as to allowthe device to be stacked side by side and end to end with minimal wastedspace thereby achieving space efficient storage at low temperatureswhich results in a reduced operating cost.

A further object of the present invention is to provide a device ascharacterized above which has two parallel planar surfaces which make upa high percentage of the total exterior surface of the container suchthat when two or more such containers, lowered to subzero temperatures,are placed in contact with each other along these large planar surfaces,the percentage of the total surface area of the combined containersavailable to absorb heat from a surrounding warmer medium issubstantially reduced.

Viewed from a first vantage point, it is an object of the presentinvention to provide a bag comprising, in combination: a first bagportion having a substantially planar outer wall, a radiused edge wallcircumscribing the planar outer wall and peripheral flashingcircumscribing the radiused edge wall, a second bag portion sealed tothe peripheral flashing and overlying the planar outer wall of the firstbag portion such that the planar outer wall is spaced from the secondbag portion by a dimension at least equal to a radius of the radiusededge wall.

Viewed from a second vantage point, it is an object of the presentinvention to provide a method for forming a bag, the steps including:forming a first mold having a recess including a planar surface, aradiused periphery circumscribing the planar surface and a peripheralledge circumscribing the radiused periphery and oriented parallel to theplanar surface, placing a blank of sheet material over the first mold,and causing the blank to conform to the mold, removing the formed sheetand enclosing the bag.

Viewed from a third vantage point, it is an object of the presentinvention to provide a bag formed by: deforming a first sheet ofmaterial to have a planar outer wall, a radiused edge wallcircumscribing the outer wall and peripheral flashing circumscribing theedge wall oriented parallel to the outer wall and defining a pocket,sealing the pocket with a second sheet of material.

Viewed from a fourth vantage point, it is an object of the presentinvention to provide a mold for forming bags comprising, in combination:a recess including a planar surface, a radiused periphery circumscribingthe planar surface and a peripheral ledge circumscribing the radiusedperiphery and oriented parallel to the planar surface, means forreceiving a blank of sheet material over the recess and lapped atop theperipheral ledge, and means for conforming the sheet material blank to acontour of the mold.

These and other objects will be made manifest when considering thefollowing detailed specification when taken in conjunction with theappended drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a female mold according to the presentinvention.

FIG. 2 is a side view of one type of bag that can be formed from themold of FIG. 1.

FIG. 3 is a perspective view of FIG. 2.

FIG. 4 is an end view of FIG. 2.

FIG. 5 is an alternate to FIG. 4.

FIGS. 6(A-C) are perspective views of a first bag portion (6A), a secondbag portion (6B) and the two portions placed in mating registry (6C).

FIG. 7 is a perspective view of a mold plug.

FIG. 8 reflects prior art bag structure and forces generated in priorart bags.

FIG. 9 is a perspective view of an alternative to FIGS. 2 through 5.

FIG. 10 is a front view of FIG. 9.

FIG. 11 is a top view of FIG. 10.

FIG. 12 is an end view of FIG. 10.

FIG. 13 reflects prior art technology in anchoring a port tube into aFIG. 8 type prior art bag.

FIG. 14 reflects sealing structure and methodology for a port tubecommunicating through the bag according to one form of the presentinvention.

FIG. 15 depicts the improvement over FIG. 8.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, wherein like reference numerals denote likeparts throughout the various drawing figures, reference numeral 10 isdirected to the bag according to the present invention.

In its essence, the bag is formed from a first half and a second half.Preferably each half includes a planar outer wall and a peripherallydisposed radiused edge wall that terminates in peripheral flashing, theflashing oriented parallel to and spaced from the planar outer wall bythe dimension of the radius. In a preferred form, each half forming thebag is a symmetrical mirror image of the other so that the overallthickness of the bag is twice the radius of either half. In another formof the invention, however, the bag can be formed as having a first halfas above-described and a second half as a planar back wall overlying arecess formed by the first half and adhered to the first half by theperipheral flashing.

More particularly, the bag as shown in FIGS. 2 through 4 include aplanar outer wall 2 which terminates in a peripherally disposed edgewall 4 having a constant radius of curvature and terminating in aperipheral flashing 6 oriented substantially parallel to the planarouter wall 2. Thus, the peripheral flashing 6 is spaced from the planarouter wall 2 by the radius defining the radiused edge wall 4 anddefining the recess therein.

FIG. 2 further reflects an inlet tube 121 formed with a series ofnecked-down constrictions 123 along its length. This tube 121 can storesamples of the contents of the bag 10 where each sample 125a, 125b,125c, etc. can be sequestered from adjacent samples by sealing at thenearest constriction 123.

FIG. 5 shows the version where the second half is formed from a planarsheet 8 with the first half as described for FIGS. 2 through 4. In allembodiments, access is provided to an interior of the bag by way of atleast one portal 12.

FIG. 2 and FIG. 3 each show three portals 12 allowing communication withthe interior of the bag 10. The portal is formed concurrently with thefirst and second halves when the embodiment of FIGS. 2 through 4 are tobe made. The portal 12 will appear on only one half of the bag in theFIG. 5 embodiment. FIG. 2 and FIG. 3 also reflect a sealed area 14 whichdefines an area of demarcation between a first compartment 16 and asecond compartment 18 for the bag 10. Although illustrative, othercompartments could be provided. The compartments 16 and 18 can be placedin fluid communication by means of a passageway 20 extending at both anupper and lower extremity of the sealed portion 14. Each passageway 20can be subsequently heat sealed.

Typically, once the bag has been filled, the bag is massaged to urge thecontents into both compartments 16 and 18. Further, the bag ismanipulated to assure the segments in areas 125a, 125b, 125c, etc. arefilled. Then a heat sealer can close passageways 20 (at 21) and at eachconstriction 123. This is desirable because once the bag is stored atcryogenic temperatures, it is preferred to minimize temperature spikes.Accordingly, a cutout 15 can appear along a central portion of sealedportion 14 so that a minimum amount of time is required to severcompartment 18 from 16. Conversely, no compartments are alsocontemplated as part of the invention. Please see the bag 10' of FIGS. 9through 12 where like parts share like numerals.

FIG. 1 reflects a complementally formed female mold for allowing onehalf of the bag to be formed. As shown in FIG. 1, the female mold 30includes a contour complemental to the bag so that the bag is a truereflection of the mold. More specifically, the planar outer wall 2 ofbag 10 has its corresponding part in mold 30 as planar surface 32.Similarly, the radiused edge wall 4 of bag 10 finds its counterpart withradiused edge wall 34. Likewise, the peripheral flashing 6 finds itscounterpart at the flashing support 36. In like manner, the accessportals 12 are formed by portal recesses 42.

FIG. 6(A-C) shows first and second bag portion halves (6A, B,respectively) and assemblage (6C) of the two halves. Alternatively,FIGS. 6A and 6B could illustrate male mold halves over which planarblanks of plastic are draped and then deformed, for example, under heatand/or pressure. In such a case, the outer wall 2 of the bag portionsare formed by mold wall 72. Radiused edge 4 is formed with edge 74.Access portals 12 are formed via projections 82. Partition 14 finds itscounterpart in mold form 84 forming two compartments defined by 86 and88.

FIG. 14 reflects structure and methodology for placing a port tube 90into a portal 12, as shown in FIG. 6C. One peripheral flange 6 is sealedto the other using a complemental RF die 101 which circumscribes thecompartment(s) 16 (18, etc.). Where the die 101 contacts the portal 12,the die has a corresponding arcuate portion 103. Because the plasticwhich formed the portal was deformed as set forth in FIG. 1 (or 6), theplastic has uniform thickness throughout and particularly regarding thecorrect tubular shape. This results in a thicker and strongersealing--joining area, especially as compared with FIG. 13. As theplastic is heated and cooled both during fabrication and use, it willhave been stress relieved.

FIG. 7 shows a plug 57 to be received with the port tube 90 and withportal 12. The preform 57 comprises an inner first rod 53 and secondconcentric cylinder 55, connected by an annular top wall 51. Central toannular top wall 51 is a bore 59 extending partially into rod 53. Theouter cylinder 55 is shorter than the inner rod 53.

The passageway 20 (FIG. 2) that allows communication between a firstcompartment and a second compartment 18 includes a relief area definingpassageway 40 (FIG. 1) so that the first compartment forming recess 46can communicate with the second compartment forming recess 48. Apartition 49 constitutes the zone of demarcation between the adjacentcompartments.

In fabrication, a sheet of plastic material overlies the mold 30 and theplanar material is forced within the contour defined by the mold 30.This can be done by positive pressure on the side of the sheet ofmaterial opposite from the mold or it can be formed by vents V forming avacuum within the mold cavity to draw the plastic down. The formingprocess can be coupled with heat and pressure and the plastics can beformed from a family of plastics characterized by their ability todeform and retain in memory their deformed state caused by theapplication of heat and or pressure.

Where the FIG. 5 bag is to be used, a substantially planar blank ofplastic is placed in overlying registry with respect to the onepreformed half defined by one planar outer wall, radiused edge wall andperipheral flashing and is adhered thereto by means of adhesive,ultrasonic welding or other fastening techniques.

Preferably, however, a second mold having mirror symmetry to the FIG. 1mold (as in FIGS. 6A, B) allows a second half to be formed which is themirror image of the first half. Thus, the peripheral flange defined bythe peripheral flashing 6 is placed in overlying registry, aligning bothhalves (as shown in FIG. 6C) and then a welding technique can be used asmentioned above.

The radiused edge wall includes the advantages illustrated in FIG. 15.First, the planar outer wall does not have any high spots and thereforepresents a substantially uniform thickness along the entire length ofthe bag. In addition, the radiused edge wall minimizes the existence ofstress areas by dissipating focusing forces so that failure of the bagat the seam site will have been made much less likely. Finally, theperipheral flashing provides an improved purchase area for causing twohalves of the bag to be united since there is an abundance of materialeasily accessible for adherence either by an adhesive or by weldingtechnology.

Having thus described the invention, it should be apparent that numerousstructural modifications and adaptations may be resorted to withoutdeparting from the scope and fair meaning of the instant invention asset forth hereinabove and as described hereinbelow by the claims.

I claim:
 1. A medical bag mold for forming medical bags which resistbreakage especially when exposed to a phase change, comprising, incombination:a recess defined by a planar surface, a radiused peripherycircumscribing said planar surface in order to provide force dissipationof the bag at its periphery and a peripheral support circumscribing saidradiused periphery and oriented parallel to said planar surface, andmeans for conforming a plastic sheet material blank to maintain acontour of the mold such that the conformed plastic sheet materialresults in a break resistant medical bag, having a complemental planarsurface, radiused periphery and peripheral flashing circumscribing saidradiused periphery.
 2. The mold of claim 1 including a relief areaprojecting into a portion of said periphery support and a portion ofsaid radiused periphery to define an access portal into a cavity of themold for providing a portal into the formed medical bag.
 3. The mold ofclaim 1 wherein said means for conforming said plastic sheet materialblank to maintain a contour of the mold is pressure means operativelycoupled to said mold.
 4. The mold of claim 1 wherein said means forconforming said plastic sheet material blank to maintain a contour ofthe mold is heat means operatively coupled to said mold.
 5. A mold forfixing fracture resistant medical bags into a fixed shape, comprising,in combination:a substantially rectangular planar surface; a peripheralsupport spaced from and parallel to and surrounding said planar surface;and a curved wall having a slope which changes along its entire extentwhen viewed in cross-section and extending from said planar surface tosaid peripheral support providing a constant radius ring transitioningbetween the surface and said support to provide medical bags which arefracture resistant and retain the shape fixed by the mold.
 6. The moldof claim 5 including at least one partition extending perpendicularlyfrom said planar surface and dividing the mold into at least twocompartments.
 7. A vacuum forming bag mold to form fixed shape medicalbags which are resistant to fracture stress, comprising, incombination:a planar surface to receive a portion of a sheet materialblank; a peripheral support to also receive another portion of the sheetmaterial blank thereon and said support spaced from and parallel to saidplanar surface and connected by a wall which also receives a furtherportion of the sheet material blank; at least one relief area definingan access fluid receiving portal projecting from said wall and alsoreceiving another portion of the sheet material blank; and said moldincluding means for causing the sheet material blank to be recontouredand held into a molded position.
 8. The bag mold of claim 7 wherein saidwall has a slope which changes along its entire extent when viewed incross-section extending from said planar surface to said peripheralsupport.
 9. The bag mold of claim 8 including at least one partitionextending perpendicularly from said planar surface and dividing the moldinto at least two compartments.
 10. The bag mold of claim 9 including anaccess passageway between each said compartment and passing through eachsaid partition.
 11. The bag mold of claim 10 wherein said accesspassageway includes two channels per partition, one remote from theother.
 12. The bag mold of claim 11 wherein the compartments are not ofequal size.
 13. The bag mold of claim 12 wherein a larger compartmentincludes at least two relief areas defining access portals.
 14. The bagmold of claim 13 wherein a smaller compartment includes at least onerelief area defining an access portal.
 15. The bag mold of claim 14further comprising means for conforming said sheet material blank to acontour of the mold and retain the contour.
 16. The bag mold of claim 15wherein said sheet material is comprised of a plastic material.
 17. Themold of claim 16 including a sheet material forming cutout on thepartition to provide a corresponding cutout on the sheet material.
 18. Amedical bag mold for forming medical bags comprising, in combination:amold cavity defined by a recess including a planar surface, a radiusedperiphery circumscribing said planar surface and a peripheral supportcircumscribing said radiused periphery and oriented parallel to saidplanar surface, means for permanently conforming a sheet material blankto a contour of the mold, and a relief area to define an access portalinto the mold cavity for providing a corresponding portal into theformed medical bag.
 19. The mold of claim 18 including a partitionprojecting up from said planar surface and interposed within a portionof the mold dividing the mold into at least two compartments.
 20. Themold of claim 19 including an access passageway between the first andsecond compartments and passing through the partition.
 21. The mold ofclaim 20 including a portal located addressing each of the compartments.22. The mold of claim 21 including a second mold having a mirrorsymmetry with the first mold and means for conforming said plastic sheetto a contour of the mold so that the bag formed thereby has a thicknesstwice the radius of one mold.
 23. The mold of claim 21 including asecond mold having a planar wall so that the bag formed thereby has oneplanar side.
 24. The mold of claim 22 wherein said means for conformingthe sheet material blank to a contour of the mold includes at least onevent on the mold for vacuum forming said blank of sheet material withinthe mold.
 25. The mold of claim 24 wherein the second of said twocompartments is larger than the first said compartment.
 26. The mold ofclaim 25 further comprising a plurality of portals located addressingsaid larger compartment.
 27. The mold of claim 26 wherein said portalsformed are substantially cylindrical bores.
 28. The mold of claim 27wherein the mold is rigid.
 29. The mold of claim 22 wherein said meansfor conforming the sheet material blank to a contour of the moldincludes positive pressure means on the side of the sheet materialopposite the mold.
 30. The mold of claim 29 further comprising a heatingmeans to aid in contouring the blank to the mold.
 31. The mold of claim28 wherein said relief area is located along one edge of said radiusedperiphery.
 32. The mold of claim 31 wherein said plurality of portalscomprises three portals within said second larger compartment and oneportal in said first compartment.
 33. The mold of claim 32 wherein atleast one said portal is configured as an inlet tube having a series ofconstrictions along its length within which the liquid is contained,said constrictions allowing sealing thereat so that a series of liquidsamples are formed between constrictions for individual removal.
 34. Amold for forming medical bags comprising, in combination:a recessincluding a planar surface, a radiused periphery circumscribing saidplanar surface and a peripheral support circumscribing said radiusedperiphery and oriented parallel to said planar surface, means forconforming a sheet material blank to a contour of the mold such that theblank retains the mold contour, a relief area to define an access portalinto the mold cavity for providing a portal into the formed bag, apartition interposed within a portion of the mold dividing the mold intoat least two compartments, an access passageway between the first andsecond compartments and passing through said partition; and a portallocated addressing each of said compartments.
 35. A mold for formingmedical bags which hold fluids used in a medical environment comprising,in combination:a recess including a planar surface, a radiused peripherycircumscribing said planar surface and a peripheral supportcircumscribing said radiused periphery and oriented parallel to saidplanar surface, means for conforming a sheet material blank to a contourof the mold such that the blank subsequently retains the contour of themold, a relief area to define an access portal into the mold cavity forproviding a portal into the formed bag, a partition interposed within aportion of the mold dividing the mold into at least two compartments, anaccess passageway between the first and second compartments and passingthrough said partition, a portal located addressing each of saidcompartments, a second mold having a mirror symmetry with the first moldso that the medical bag formed thereby has a thickness twice the radiusof one mold, wherein said means for conforming the sheet material blankto a contour of the mold includes at least one vent on the mold forvacuum forming said blank of sheet material within the mold, wherein thesecond of said two compartments is larger than the first saidcompartment, and further comprising a plurality of portals locatedaddressing said larger compartment.
 36. A mold for forming medical bagscomprising, in combination:a recess including a planar surface, aradiused periphery circumscribing said planar surface and a peripheralsupport circumscribing said radiused periphery and oriented parallel tosaid planar surface, and means for conforming a sheet material blank toa contour of the mold such that the blank subsequently retains thecontour of the mold, including a relief area to define an access portalinto the mold cavity for providing a portal into the formed bag, apartition interposed within a portion of the mold dividing the mold intoat least two compartments, an access passageway between the first andsecond compartments and passing through said partition, a portal locatedaddressing each of said compartments, a second mold having a mirrorsymmetry with the first mold so that the medical bag formed thereby hasa thickness twice the radius of one mold, wherein said means forconforming the sheet material blank to a contour of the mold includes atleast one vent on the mold for vacuum forming said blank of sheetmaterial within the mold, wherein the second of said two compartments islarger than the first said compartment, further comprising a pluralityof portals located addressing said larger compartment, wherein saidportals formed are substantially cylindrical bores, wherein the mold isrigid, wherein said relief area is located along one edge of saidradiused periphery, and wherein said plurality of portals comprisesthree portals within said second larger compartment and one portal insaid first compartment.
 37. A mold for forming medical bags, comprising,in combination:a planar surface; a peripheral support spaced from saidplanar surface; a curved wall having a slope which changes along itsentire extent when viewed in cross section extending from said planarsurface to said peripheral support; at least one partition extendingperpendicularly from said planar surface and dividing the mold into atleast two compartments; an access passageway between each saidcompartment and passing through each said partition; wherein said accesspassageway includes two channels, one remote from the other; and atleast one relief area defining an access portal in at least onecompartment of the mold.
 38. A mold for forming medical bags,comprising, in combination:a planar surface; a peripheral support spacedfrom said planar surface; a curved wall having a slope which changesalong its entire extent when viewed in cross section extending from saidplanar surface to said peripheral support; at least one partitionextending perpendicularly from said planar surface and dividing the moldinto two compartments; an access passageway between each saidcompartment and passing through each said partition; wherein said accesspassageway includes two channels, one remote from the other; at leastone relief area defining an access portal in at least one compartment ofthe mold; wherein one of said two compartments is larger than the othersaid compartment; and wherein the larger said compartment includes atleast two relief areas defining access portals.
 39. The mold of claim 38wherein said smaller compartment includes at least one relief areadefining an access portal.
 40. A mold for forming medical bagscomprising, in combination:a recess including a planar surface, aradiused periphery circumscribing said planar surface and a peripheralsupport circumscribing said radiused periphery and oriented parallel tosaid planar surface, means for conforming a sheet material blank to acontour of the mold such that the blank subsequently conforms to thecontour of the mold, a partition interposed within a portion of the molddividing the mold into at least two compartments, and a portal locatedaddressing each of said compartments.
 41. A mold for forming medicalbags comprising, in combination:a recess including a planar surface, aradiused periphery circumscribing said planar surface and a peripheralsupport circumscribing said radiused periphery and oriented parallel tosaid planar surface, means for conforming a sheet material blank to acontour of the mold such that the blank subsequently conforms to thecontour of the mold, a relief area to define an access portal into themold cavity for providing a portal into the formed bag, a partitioninterposed within a portion of the mold dividing the mold into at leasttwo compartments, an access passageway between the first and secondcompartments and passing through said partition, a portal locatedaddressing each of said compartments, a second mold having a mirrorsymmetry with the first mold so that the medical bag formed thereby hasa thickness twice the radius of one mold, wherein said means forconforming the sheet material blank to a contour of the mold includes atleast one vent on the mold for vacuum forming said blank of sheetmaterial within the mold, wherein the second of said two compartments islarger than the first said compartment, further comprising a pluralityof portals located addressing said larger compartment, and wherein saidplurality of portals comprises three portals within said second largercompartment and one portal in said first compartment.
 42. A mold forforming medical bags, comprising, in combination:a planar surface; aperipheral support spaced from said planar surface; a curved wall havinga slope which changes along its entire extent when viewed in crosssection extending from said planar surface to said peripheral support;at least one partition extending perpendicularly from said planarsurface and dividing the mold into at least two compartments; andincluding at least one relief area defining an access portal in at leastone compartment of the mold.
 43. The mold of claim 42 wherein one ofsaid two compartments is larger than the other said compartment,andwherein the larger said compartment includes at least two reliefareas defining access portals.
 44. A mold for forming medical bags,comprising, in combination:a planar surface; a peripheral support spacedfrom said planar surface; and a curved wall having a slope which changesalong its entire extent when viewed in cross section extending from saidplanar surface to said peripheral support, at least one partitionextending perpendicularly from said planar surface and dividing the moldinto two compartments, an access passageway between each saidcompartment and passing through each said partition, wherein said accesspassageway includes two channels, one remote from the other, at leastone relief area defining an access portal in at least one compartment ofthe mold, wherein one of said two compartments is larger than the othersaid compartment, and wherein said smaller compartment includes at leastone relief area defining an access portal.
 45. A mold for formingfracture resistant medical bags which retain the shape of the mold,comprising, in combination:a substantially rectangular planar surface; aperipheral support spaced from and parallel to and surrounding saidplanar surface; a curved wall having a slope which changes along itsentire extent when viewed in cross section extending from said planarsurface to said peripheral support providing a constant radius ringtransitioning between the surface and said support; and including atleast one partition extending perpendicularly from said planar surfaceand dividing the mold into at least two compartments.
 46. The mold ofclaim 45 including an access passageway between each said compartmentand passing through each said partition.
 47. The mold of claim 46wherein said access passageway includes two channels, one remote fromthe other.
 48. The mold of claim 47 including at least one relief areadefining an access portal in at least one compartment of the mold. 49.The mold of claim 48 wherein the mold includes two compartments.
 50. Themold of claim 49 wherein one of said two compartments is larger than theother said compartment.
 51. The mold of claim 50 wherein the larger saidcompartment includes at least two relief areas defining access portals.52. The mold of claim 51 wherein said smaller compartment includes atleast one relief area defining an access portal.
 53. The mold of claim52 further comprising means for conforming a plastic sheet materialblank to a contour of the mold.
 54. The mold of claim 48 furthercomprising a second mold complemental to said first mold and a mirrorimage thereof for forming a complete bag.
 55. The mold of claim 54including a portal located addressing each of the compartments.
 56. Avacuum forming medical bag mold, comprising, in combination:a planarsurface; a peripheral support to receive a sheet material blank thereonand said support spaced from and parallel to said planar surfaceconnected by a wall; at least one relief area defining an access fluidreceiving portal projecting from said wall; wherein said wall has aslope which changes along its entire extent when viewed in cross-sectionextending from said planar surface to said peripheral support; andincluding at least one partition extending perpendicularly from saidplanar surface and dividing the mold into at least two compartments.